CVE-2026-56131

MEDIUMPre-NVD 4.94.9—
EchelonGraph scoreMEDIUM confidence

Score 4.9 from GitHub Security Advisory published 2026-06-19. a secondary CVSS source baseline 4.9; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
4.9EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 4.9Exploit: None knownExposed: 0

A fix is available — apply it.

libexpat before 2.8.2 lacks handler call depth tracking for calls to XML_ResumeParser from within handlers in cases of a policy violation. Thus, a use-after-free can occur (similar to the CVE-2026-50219 situation).

CVSS v3
4.9
EG Score
4.9(medium)
EG Risk
27(Track)
EG Risk 27/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity49% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
7%
KEV
Not listed

Published

June 19, 2026

Last Modified

June 23, 2026

Advisory Details (1)

Auto-updated Jun 22, 2026
Upstream fix merged — awaiting tagged release. Sources: github_pr.
github_pr

[CVE-2026-56131] lib: Protect `XML_ResumeParser` from being called from a handler

Fix merged in libexpat/libexpat PR #1267 on 2026-06-20 — awaiting tagged release

https://github.com/libexpat/libexpat/pull/1267

Vendor Advisories for CVE-2026-56131(3)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatexpat-main-2.8.2-1.1.hum12026-07-15redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(8 across 8 ecosystems)
Alpine:v3.21(1)
PackageVulnerable rangeFixed inDependents
expat—2.8.2-r0—
Alpine:v3.22(1)
PackageVulnerable rangeFixed inDependents
expat—2.8.2-r0—
Alpine:v3.23(1)
PackageVulnerable rangeFixed inDependents
expat—2.8.2-r0—
Alpine:v3.24(1)
PackageVulnerable rangeFixed inDependents
expat—2.8.2-r0—
Debian:11(1)
PackageVulnerable rangeFixed inDependents
expat2.2.10-2 ... 2.8.2-1~deb13u1 (47 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
expat2.5.0-1, 2.5.0-1+deb12u1, 2.5.0-1+deb12u22.5.0-1+deb12u3—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
expat2.7.1-2 ... 2.8.1-1 (9 versions)2.8.2-1~deb13u1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
expat2.7.1-2 ... 2.8.2-1~deb13u1 (10 versions)2.8.2-1—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 6× in last 7d / 37× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 213 total refreshes for this CVE.

  1. 2026-09-20 20:16 UTCEPSS rescore
  2. 2026-09-18 19:28 UTCEPSS rescore
  3. 2026-09-17 19:31 UTCEPSS rescore
  4. 2026-09-16 14:08 UTCEPSS rescore
  5. 2026-09-16 05:15 UTCEPSS rescore
  6. 2026-09-15 03:11 UTCEPSS rescore
  7. 2026-09-13 16:47 UTCEPSS rescore
  8. 2026-09-13 13:31 UTCEG score recompute
  9. 2026-09-13 13:31 UTCVendor advisory
  10. 2026-09-13 13:31 UTCGHSA enrichment
  11. 2026-09-11 14:53 UTCEPSS rescore
  12. 2026-09-10 09:35 UTCEPSS rescore
  13. 2026-09-08 22:01 UTCEPSS rescore
  14. 2026-09-07 16:01 UTCEPSS rescore
  15. 2026-09-06 13:47 UTCEPSS rescore
  16. 2026-09-04 05:07 UTCEPSS rescore
  17. 2026-09-02 14:12 UTCEPSS rescore
  18. 2026-09-01 13:54 UTCEPSS rescore
  19. 2026-09-01 04:40 UTCEPSS rescore
  20. 2026-08-30 20:53 UTCEG score recompute
  21. 2026-08-30 20:53 UTCVendor advisory
  22. 2026-08-30 20:53 UTCGHSA enrichment
  23. 2026-08-30 19:17 UTCEPSS rescore
  24. 2026-08-30 01:22 UTCEPSS rescore
  25. 2026-08-28 21:41 UTCEPSS rescore
Show 75 more
  1. 2026-08-27 14:25 UTCEPSS rescore
  2. 2026-08-26 14:46 UTCEPSS rescore
  3. 2026-08-25 13:49 UTCEPSS rescore
  4. 2026-08-25 06:05 UTCEG score recompute
  5. 2026-08-25 06:05 UTCVendor advisory
  6. 2026-08-25 06:05 UTCGHSA enrichment
  7. 2026-08-24 05:08 UTCVendor advisory
  8. 2026-08-24 05:08 UTCGHSA enrichment
  9. 2026-08-23 01:02 UTCEG score recompute
  10. 2026-08-23 01:02 UTCVendor advisory
  11. 2026-08-23 01:02 UTCGHSA enrichment
  12. 2026-08-23 00:19 UTCEPSS rescore
  13. 2026-08-21 23:49 UTCEPSS rescore
  14. 2026-08-21 09:27 UTCEG score recompute
  15. 2026-08-21 09:27 UTCVendor advisory
  16. 2026-08-21 09:27 UTCGHSA enrichment
  17. 2026-08-20 22:55 UTCEPSS rescore
  18. 2026-08-20 08:18 UTCEG score recompute
  19. 2026-08-20 08:18 UTCVendor advisory
  20. 2026-08-20 08:18 UTCGHSA enrichment
  21. 2026-08-19 17:04 UTCEPSS rescore
  22. 2026-08-19 07:21 UTCEG score recompute
  23. 2026-08-19 07:21 UTCVendor advisory
  24. 2026-08-19 07:21 UTCGHSA enrichment
  25. 2026-08-18 13:48 UTCEPSS rescore
  26. 2026-08-17 13:47 UTCEPSS rescore
  27. 2026-08-17 04:21 UTCEG score recompute
  28. 2026-08-17 04:21 UTCVendor advisory
  29. 2026-08-17 04:21 UTCGHSA enrichment
  30. 2026-08-16 14:56 UTCEPSS rescore
  31. 2026-08-16 03:24 UTCEG score recompute
  32. 2026-08-16 03:24 UTCVendor advisory
  33. 2026-08-16 03:24 UTCGHSA enrichment
  34. 2026-08-16 02:14 UTCEPSS rescore
  35. 2026-08-15 02:27 UTCEG score recompute
  36. 2026-08-15 02:27 UTCVendor advisory
  37. 2026-08-15 02:27 UTCGHSA enrichment
  38. 2026-08-15 01:30 UTCEPSS rescore
  39. 2026-08-14 01:31 UTCEG score recompute
  40. 2026-08-14 01:31 UTCVendor advisory
  41. 2026-08-14 01:31 UTCGHSA enrichment
  42. 2026-08-13 22:00 UTCEPSS rescore
  43. 2026-08-13 00:35 UTCEG score recompute
  44. 2026-08-13 00:35 UTCVendor advisory
  45. 2026-08-13 00:35 UTCGHSA enrichment
  46. 2026-08-12 13:51 UTCEPSS rescore
  47. 2026-08-11 23:38 UTCEG score recompute
  48. 2026-08-11 23:38 UTCVendor advisory
  49. 2026-08-11 23:38 UTCGHSA enrichment
  50. 2026-08-11 00:00 UTCEPSS rescore
  51. 2026-08-10 22:42 UTCVendor advisory
  52. 2026-08-10 22:42 UTCGHSA enrichment
  53. 2026-08-09 21:45 UTCEG score recompute
  54. 2026-08-09 21:45 UTCVendor advisory
  55. 2026-08-09 21:45 UTCGHSA enrichment
  56. 2026-08-09 13:46 UTCEPSS rescore
  57. 2026-08-08 20:49 UTCEG score recompute
  58. 2026-08-08 20:49 UTCVendor advisory
  59. 2026-08-08 20:49 UTCGHSA enrichment
  60. 2026-08-08 16:37 UTCEPSS rescore
  61. 2026-08-07 19:52 UTCEG score recompute
  62. 2026-08-07 19:52 UTCVendor advisory
  63. 2026-08-07 19:52 UTCGHSA enrichment
  64. 2026-08-06 18:56 UTCEG score recompute
  65. 2026-08-06 18:56 UTCVendor advisory
  66. 2026-08-06 18:56 UTCGHSA enrichment
  67. 2026-08-06 13:47 UTCEPSS rescore
  68. 2026-08-05 19:17 UTCEPSS rescore
  69. 2026-08-05 17:59 UTCVendor advisory
  70. 2026-08-05 17:59 UTCGHSA enrichment
  71. 2026-08-04 15:22 UTCEG score recompute
  72. 2026-08-04 15:22 UTCVendor advisory
  73. 2026-08-04 15:22 UTCGHSA enrichment
  74. 2026-08-04 15:10 UTCEPSS rescore
  75. 2026-08-04 10:39 UTCEPSS rescore

Related CVEs(same vendor + same CWE)

Same vendor

2 shown

redhat:RHSA-2026:40486

Frequently asked(5)

What is CVE-2026-56131?
CVE-2026-56131 is a medium vulnerability published on June 19, 2026. libexpat before 2.8.2 lacks handler call depth tracking for calls to XML_ResumeParser from within handlers in cases of a policy violation. Thus, a use-after-free can occur (similar to the CVE-2026-50219 situation).
When was CVE-2026-56131 disclosed?
CVE-2026-56131 was first published in the National Vulnerability Database on June 19, 2026, with the most recent update on June 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-56131 actively exploited?
CVE-2026-56131 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 92.7% of all scored CVEs.
What is the CVSS score of CVE-2026-56131?
CVE-2026-56131 has a CVSS v3 base score of 4.9 (NVD).
How do I remediate CVE-2026-56131?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-56131, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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